CN112959855A

CN112959855A - Inner core butt joint integrally-formed spoke and preparation method thereof

Info

Publication number: CN112959855A
Application number: CN202110307239.3A
Authority: CN
Inventors: 刘五瑞
Original assignee: Xiamen Carbon Ying Composite Material Technology Co ltd
Current assignee: Xiamen Carbon Ying Composite Material Technology Co ltd
Priority date: 2021-03-23
Filing date: 2021-03-23
Publication date: 2021-06-15

Abstract

The invention discloses an inner core butt joint integrally-formed spoke and a preparation method thereof, wherein the spoke comprises a first carbon rod inner core and a second carbon rod inner core, the heads of the two carbon rod inner cores are formed into enlarged parts with gradually changed diameters, two metal pieces are sleeved into the corresponding carbon rod inner cores and moved in place, the tail part of the first carbon rod inner core is butt jointed with the tail part of the second carbon rod inner core, the first metal piece is arranged at the head part of the first carbon rod inner core, and the second metal piece is arranged at the head part of the second carbon rod inner core; and winding and coating the carbon fiber prepreg, and heating and molding. The invention adopts the process of winding and coating two sections or two sections of carbon rods and metal parts by the carbon fiber prepreg, so that a sandwich structure is formed between the metal parts and the carbon fiber materials to increase the bonding interface between the spoke body and the metal part caps and the cap heads at two ends, the bonding force between the spoke body and the metal parts at two ends is greatly improved, and meanwhile, the spoke inner core and the metal parts are bonded by an inverted cone structure, so that the spoke body and the metal parts cannot slip off, and the structural strength of the product is improved.

Description

Inner core butt joint integrally-formed spoke and preparation method thereof

Technical Field

The invention discloses an inner core butt joint integrally-formed spoke and a preparation method thereof, belonging to the technical field of wheel spoke manufacturing according to the division of an International Patent Classification (IPC).

Background

In a bicycle system, spokes are bridges that connect a rim to a hub. In the use process, one end of each spoke is provided with a cap head and connected to the hub, and the other end of each spoke is provided with a screw tooth and locked with the spoke cap and connected to the rim. During the running process of the bicycle, all the bearing pressure is provided by the tension generated by assembling the spokes on the hub and the rim, so the performance of the spokes is good or bad, and the performance of the whole bicycle is directly influenced. The existing spokes are generally made of stainless steel, titanium, aluminum and other materials, and the spokes are quite heavy, so that the requirements of increasingly lightening the weight of products are not facilitated. Carbon fiber composite materials (CFRP) are used as the material of spokes, and the production and manufacturing processes of different factories are different.

At present, the mainstream carbon fiber spoke manufacturing method is to form a spoke main body by using a die or other methods, and then metal parts are adhered to two ends of the spoke, so that the spoke has the function of a spoke. For example, chinese document CN205273028U discloses a carbon fiber spoke including a spoke body, one end of the spoke body is connected to a first fitting that can be connected to a rim in a fitting manner, the other end of the spoke body is connected to a second fitting that can be connected to a hub in a fitting manner, and the spoke body is made of carbon fiber. This end of body of spoke and the connection between the accessory adopt the bonding mode, and in the use, hub, rim can produce the pulling force and act on the accessory, make the accessory be easy to be pulled from the spoke body, lead to the two separation, and life is short, and the security is not enough, also can increase cost of maintenance.

The carbon fiber spoke in chinese document CN209365753U includes a spoke body, and a hub connecting portion and a rim connecting portion respectively connected to two ends of the spoke body, wherein the spoke body is integrally connected to the hub connecting portion, a connecting member is fixedly sleeved on an outer peripheral side of a connection portion of the spoke body and the rim connecting portion, and an extending portion extends from a side wall of the connecting member along an axial direction of the spoke body. The spoke body with the truncated cone-shaped fastening piece has high process requirement, complex manufacturing die, low manufacturing efficiency and high manufacturing cost, and is basically not suitable for industrial production. Even the spoke body can make, the connecting piece middle part is seted up the inner wall and is set up the inserting groove degree of difficulty height of screw thread and has destroyed the fibrous continuity of body, and it is big to the tensile strength destruction of spoke, and the screw thread strength of combined material inner wall hardly satisfies the requirement of bonding strength in addition, so is pulled easily between rim connecting portion and the spoke body and takes off, and intensity and security can be not enough.

Also for example, CN107972403A is a carbon fiber spoke and a manufacturing method thereof, the carbon fiber spoke includes a spoke body, a tooth cap and a cap head; the outer peripheral surface of the fixed joint is provided with a first taper section which is arranged inside and outside and has a small inside and a large outside and a first rotary section, and the outer diameter of the first rotary section is not larger than the maximum outer diameter of the first taper section; the tooth cap and the cap head are provided with through mounting holes, the hole wall of each mounting hole is provided with a second rotary section and a second taper section, the inner diameter of the second rotary section is gradually increased from near to far relative to the second rotary section, the second rotary section of each mounting hole is sleeved on the spoke body, and the second taper section of each mounting hole is sleeved on the fixed connection head. The interface of the stress structure is only the combination between the peripheries of the two ends of the spoke body and the mounting hole walls of the tooth cap and the cap head, if the combination between the fixed yarn sheet and the spoke body is not good, the tooth cap or the cap sleeve is pulled out in the test or use process, and the safety risk exists; on the other hand, the size requirement of the material removing processing of the consolidation head is very accurate, the processing difficulty is high, otherwise, the requirement cannot be met by matching with the mounting holes of the dental cap and the cap head.

In addition, the metal parts of the spokes in the current market are large in size, and the whole manufactured spoke is heavy; the size of the metal piece is large, the hole diameter of the hub and the rim which are matched with each other is increased, and the strength is weakened under the same condition.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides an inner core butt joint integrally-formed spoke.

In order to achieve the purpose, the invention is realized by the following technical scheme:

the utility model provides an inner core butt joint integrated into one piece spoke, it includes first carbon-point inner core, second carbon-point inner core and carbon fiber prepreg layer, first carbon-point inner core butt joint second carbon-point inner core, the outer end of first carbon-point inner core and second carbon-point inner core is the great end of diameter and overlaps respectively and establishes cap head and dental cap, first carbon-point inner core, second carbon-point inner core and dental cap, the cap head is equipped with carbon fiber prepreg layer outward, wherein the cap head is equipped with the head of cooperation connection flower-drum, the dental cap is equipped with the thread portion of cooperation connection rim, the head of cap head and the thread portion of dental cap are located the outside of carbon fiber prepreg layer.

Further, the carbon fiber prepreg layer is formed by winding the carbon fiber prepreg on the first carbon rod inner core, the second carbon rod inner core, the dental cap and the cap head and heating in a mold;

the outer ends of the first carbon rod inner core and the second carbon rod inner core are of inverted cone structures.

Further, a mounting hole is formed in the center of the cap head and comprises a conical hole section and a straight hole section, wherein the maximum inner diameter of the conical hole section is smaller than the maximum outer diameter of the first carbon rod inner core inverted cone structure;

the center of the tooth cap is provided with a mounting hole which comprises a taper hole section and a straight hole section, wherein the maximum inner diameter of the taper hole section is smaller than the maximum outer diameter of the inverted cone structure of the second carbon rod inner core.

Furthermore, the cap head and the dental cap are provided with conical extending parts for winding and connecting the carbon fiber prepreg, and anti-falling bosses are arranged on the peripheries of the conical extending parts of the cap head and the dental cap so as to improve the binding force of the carbon fiber prepreg coating.

The invention also provides a preparation method of the spoke formed by integrally butting the inner cores.

A preparation method of an inner core butt joint integrally-formed spoke comprises the following steps:

s1, preparing a carbon rod inner core:

the carbon rod inner core is divided into a first carbon rod inner core and a second carbon rod inner core, one end of each of the two carbon rod inner cores is a head part, the other end of each of the two carbon rod inner cores is a tail part, the two carbon rod inner cores extend from the tail part to the head part to form a cylinder, and the head part is formed into an enlarged part with gradually changed diameter;

s2, preparing a first metal piece and a second metal piece at two ends of the spoke, wherein the centers of the two metal pieces are provided with axial through holes, and the through holes are matched with the first carbon rod inner core and the second carbon rod inner core;

s3, sleeving the first metal piece on the tail part of the first carbon rod inner core and moving the first metal piece to a position,

the second metal piece is sleeved in the tail part of the second carbon rod inner core and is moved to the right position,

the tail part of the first carbon rod inner core is butted with the tail part of the second carbon rod inner core, the first metal piece is arranged at the head part of the first carbon rod inner core, and the second metal piece is arranged at the head part of the second carbon rod inner core;

s4, wrapping the first carbon rod inner core and the second carbon rod inner core, the first metal piece and the second metal piece by carbon fiber prepreg to form a semi-finished product;

s5, placing the wound semi-finished product into a forming die for heating and forming;

and S6, opening the mold after molding, taking out and trimming, and then processing a screw tooth on the second metal piece to obtain the final usable product.

In step S1, the first carbon rod inner core and the second carbon rod inner core are carbon rod inner cores of the same specification, and a carbon fiber rod body is formed by die molding or pultrusion, and the diameter of the cylinder part of the carbon rod inner core is smaller than 1.8 mm.

In step S2, the peripheries of the opposite ends of the first metal piece and the second metal piece are both tapered, and the through hole in the middle of the two metal pieces includes a tapered section to match with the enlarged portion of the corresponding carbon rod inner core.

In step S2, the first metal part and the second metal part are both processed into a concave-convex design to improve the bonding force of the carbon fiber prepreg coated metal part, and the second metal part is provided with a linear slot on the outside of the concave-convex design, which can be used as a fixing function to prevent twisting when a nut is screwed down later.

Before step S3, two metal pieces and the corresponding carbon rod inner core need to be coarsened, and the surface of the head of the carbon rod inner core is coated with high-strength high-temperature-resistant bonding glue and is connected and bonded with the corresponding metal pieces;

in step S4, the carbon fiber prepreg with the cross angle is used for winding and wrapping, and the first metal piece or the second metal piece is wound in layers from the position with the slope until the required thickness is designed.

In step S5, the temperature is controlled at 180 ℃ for 50-70 minutes during the heating and forming.

In step S5, the spoke shape is a circular or flat shape or an oval or substantially diamond cross-sectional shape.

In step S6, the screw thread end of the second metal piece on the spoke is matched with and assembled with a screw cap, and the first metal piece of the spoke has a cap head structure.

The invention relates to an inner core butt joint integrally-formed spoke and a preparation method thereof.A process of winding and coating two or two sections of carbon rods (namely spoke inner cores) and metal parts by using carbon fiber prepreg is adopted, so that a sandwich structure is formed between the metal parts and carbon fiber materials to increase the bonding interface between a spoke body and tooth caps and cap heads of the metal parts at two ends, the bonding force between the spoke body and the metal parts at two ends is greatly improved, meanwhile, the spoke inner cores and the metal parts are bonded by an inverted cone structure, the spoke body and the metal parts are ensured not to slip, and the structural strength of a product is improved.

Drawings

FIG. 1 is a schematic illustration of spoke use.

Fig. 2 is a cross-sectional view of an embodiment of the present invention.

FIG. 3 is a schematic view of the butt joint of the carbon rod inner core according to the present invention.

Fig. 4 is an assembly pattern of a first metal piece cap head and a carbon rod core according to the present invention.

Fig. 5 shows the assembly pattern of the cap of the second metal piece of the present invention and the core of the carbon rod.

FIG. 6 is a diagram illustrating the butt joint of the carbon rod inner core and two metal parts after the carbon rod inner core and the two metal parts are assembled according to the embodiment of the invention.

FIG. 7 is a cross-sectional view after molding of an embodiment of the present invention.

Fig. 8 is a partial cross-sectional view of a first metal piece cap after forming in accordance with an embodiment of the present invention.

FIG. 9 is a partial cross-sectional view of a second metal dental cap in accordance with an embodiment of the present invention after formation.

Detailed Description

The invention will be further described with reference to the accompanying drawings in which:

example (b): the utility model provides an integrated into one piece carbon fiber spoke, its includes one by the spoke inner core that carbon fiber made, one can cooperate the dental cap (second metalwork 4) of connecting wheel rim (rim) and one can cooperate the cap head (first metalwork 3) and the carbon fiber prepreg layer 5 of connecting the flower drum, dental cap and cap head be equipped with the mounting hole that runs through, the mounting hole of this dental cap and the mounting hole of cap head are fixed the cup respectively at the both ends of spoke inner core, spoke inner core and partial metal dental cap and cap head are equipped with the carbon fiber prepreg layer outward, spoke inner core and carbon fiber prepreg layer integrated into one piece are the spoke body. The spoke inner core can be of an integral structure, namely, the spoke inner core is of an integral structure from a cap head to a dental cap, the spoke inner core can also be of a butt joint type structure, as shown in fig. 3, the spoke inner core is in butt joint with a first carbon rod inner core 1 and a second carbon rod inner core 2, and the scheme of integrally forming the spokes in the butt joint mode is described below.

Referring to fig. 2 to 9, an inner core butt joint integrally-formed spoke includes a first carbon rod inner core 1, a second carbon rod inner core 2 and a carbon fiber prepreg layer 5, the first carbon rod inner core 1 is in butt joint with the second carbon rod inner core 2, the outer ends of the first carbon rod inner core and the second carbon rod inner core are larger in diameter and are respectively sleeved with a cap head (a first metal part 3) and a nut (a second metal part 4), the first carbon rod inner core 1, the second carbon rod inner core 2, the nut and the cap head are externally provided with the carbon fiber prepreg layer 5, wherein the cap head is provided with a head portion in fit connection with a hub, the nut is provided with a thread portion in fit connection with a rim, and the head portion of the cap head and the thread portion of the nut are located outside the carbon fiber prepreg layer. The outer end of first carbon-point inner core 1 and second carbon-point inner core 2 is the back taper structure: as shown in FIG. 4, the maximum diameter D of the first carbon rod inner core, the outer diameter D of the other part of the first carbon rod inner core, and the outer diameter of the minimum end of the first carbon rod inner core are D, wherein D/D is more than or equal to 2 and more than or equal to 1.3; as shown in FIG. 5, the maximum diameter D of the second carbon rod inner core, the outer diameter D of the other part of the first carbon rod inner core and the outer diameter of the minimum end of the second carbon rod inner core are D, and D/D is more than or equal to 2 and more than or equal to 1.3. Correspondingly, the center of the cap head is provided with a mounting hole, the mounting hole comprises a taper hole section 31 and a straight hole section 32, wherein the maximum inner diameter of the taper hole section 31 is smaller than the maximum outer diameter of the first carbon rod inner core inverted cone structure 11; the center of the dental cap is provided with a mounting hole, the mounting hole comprises a taper hole section 41 and a straight hole section 42, and the maximum inner diameter of the taper hole section 41 is smaller than the maximum outer diameter of the inverted conical structure 21 of the second carbon rod inner core. The carbon fiber prepreg layer 5 is formed by winding the carbon fiber prepreg on the first carbon rod inner core 1, the second carbon rod inner core 2, the dental cap and the cap head and heating in a die. The cap head is provided with a conical extension part 33, the dental cap is provided with a conical extension part 43 for winding and connecting carbon fiber prepreg, the peripheries of the dental cap and the conical extension part of the cap head are provided with anti-falling bosses for improving the binding force of carbon fiber prepreg coating, and the anti-falling bosses can be in annular bulges or tooth-shaped structures or other concave-convex shapes.

The spoke is integrally formed by butting the inner cores, the tooth cap and the cap head are sleeved into the corresponding carbon rod inner core and then butted, carbon fiber prepreg is wound and coated, the carbon rod inner core and the carbon fiber prepreg layer are placed in a forming die to be heated and cured and shaped, the tooth cap and the cap head are respectively fixed with the spoke main body through double-layer connection, the spoke body and a metal part cannot slip, and the structural strength of a product is improved.

In use of the invention, as shown in figure 1, the outer ends of the spokes 101 are connected to the rim or rim 102, the inner ends of the spokes are connected to the hub 103, and the spokes 101 are offset from the radial connecting line M between the connecting points of the outer ends of the spokes and the center of the hub.

s1, preparing a carbon rod inner core:

the carbon rod inner core is divided into a first carbon rod inner core 1 and a second carbon rod inner core 2, one end of each of the two carbon rod inner cores is a head part, the other end of each of the two carbon rod inner cores is a tail part, the two carbon rod inner cores extend from the tail part to the head part to form a cylinder, and the head part is formed into an enlarged part with gradually changed diameter, namely an inverted cone structure;

s2, preparing a first metal piece 3 and a second metal piece 4 at two ends of the spoke, wherein the centers of the two metal pieces are provided with axial through holes, and the through holes are matched with the first carbon rod inner core and the second carbon rod inner core;

s3, sleeving the first metal piece 3 into the tail part of the first carbon rod inner core 1 and moving the first metal piece to a proper position,

the second metal piece 4 is sleeved on the tail part of the second carbon rod inner core 2 and is moved to the position,

the tail of the first carbon rod inner core 1 is butted with the tail of the second carbon rod inner core 2, the first metal piece 3 is arranged at the head of the first carbon rod inner core, and the second metal piece 4 is arranged at the head of the second carbon rod inner core;

s5, placing the wound semi-finished product into a forming die for heating and forming, and forming an outer layer 5 by using carbon fiber prepreg;

and S6, opening the mold after molding, taking out, trimming, and then processing a screw thread on the second metal piece 4 to obtain the final usable product.

In the embodiment of the present invention, the first carbon rod inner core 1 and the second carbon rod inner core 2 may be single bodies with different lengths, as shown in fig. 6, the length L1 of the first metal piece 3 is cut off by the first carbon rod inner core by the first metal piece length L2, the length L4 of the second metal piece 4 is cut off by the second carbon rod inner core by the second metal piece length L3, and the limiting conditions are that L2>2L1, and L3>2L 4. But in order to improve efficiency, can design first carbon-point inner core 1 and second carbon-point inner core 2 for the carbon-point inner core of the same specification, unified management, the same specification includes length and external diameter size etc. adopts half of whole spoke promptly in length, makes things convenient for follow-up and metalwork equipment, and the carbon-point inner core adopts the carbon fiber stick body of mould shaping or pultrusion, and the cylinder part diameter of carbon-point inner core is less than 1.8 mm.

In order to avoid the transition of the joint between the metal member and the carbon fiber core, in step S2, the outer peripheral sides of the first metal member 3 and the second metal member 4 are tapered. The through hole in the middle of the two metal pieces comprises a cone-shaped section and a straight section which are respectively matched with the inverted cone structure and the cylinder of the carbon rod inner core. In step S2, the first metal piece 3 and the second metal piece 4 are both processed to have a concave-convex design to improve the bonding force of the carbon fiber prepreg coated metal piece. The second metal part 4 is provided with a linear clamping groove 44 on the outer side of the concave-convex design, and can be used for fixing when a nut is screwed later, so that the torsion is prevented.

In an embodiment of the present invention, gluing and carbon fiber prepreg coating are further adopted to be used in combination to improve the bonding force, and before step S3, the two metal pieces and the inner core of the carbon rod need to be roughened, wherein the roughening is mainly surface treatment, and the metal pieces are sand-blasted. The surface of the carbon rod inner core is coated with high-strength high-temperature-resistant joint glue and is connected with the two metal pieces, the glue is mainly applied to the positions where the two ends of the carbon fiber core body are combined with the metal pieces, and the glue can be the whole carbon rod.

In step S4, in an embodiment of the present invention, a carbon fiber prepreg with a cross angle is used for winding and coating, and the carbon fiber core and the metal part are wound and coated in layers from a position with a slope of the first metal part or the second metal part to a designed and required thickness, where the cross is formed by winding/coating the carbon fiber core and the metal part with the carbon fiber prepreg with a 0 degree or a belt angle.

In step S5 of one embodiment of the present invention, during the heating and forming, the temperature is controlled at 180 ℃, preferably 155 ℃, and the heating time is controlled at 50-70 minutes, preferably 60 mins; the spoke shape is a round or flat shape or an oval or rhombus-like cross-sectional shape.

In an embodiment of the present invention, the first metal part 3 is referred to as a cap head, the second metal part 4 is referred to as a nut cap, the threaded end of the second metal part on the spoke is matched with a nut to connect with the rim, and the first metal part of the spoke has a cap head structure to connect and fix with the hub.

The carbon spoke of the embodiment of the invention has the following difference compared with the existing metal spoke:

the data are obtained by testing with a universal material tester.

The integrally formed carbon fiber spoke has the following characteristics:

1. a method for preparing spokes integrally formed by butting inner cores does not need subsequent processing such as yarn fixing, adhesion and the like;

2. the smaller part of the aperture of the middle hollow part of the metal part tooth cap and the cap head is smaller than 1.8mm, the diameter of the carbon rod cylinder is smaller than 1.8mm, the two metal parts penetrate from the smaller end of the carbon rod respectively, and the metal parts are combined more firmly under the action of pulling force at the larger end.

3. The first metal piece and the second metal piece, namely the cap head and the tooth cap, have small sizes, can adapt to the existing hub and rim with small apertures on the market, and have the advantages of small aperture, assembly and matching of the frame and enhanced strength.

4. The invention overcomes the defects of low bonding strength of carbon fiber spoke gluing, changes the combination mode between the spoke body and metal parts at two ends, adopts double-layer connection relation or even three-layer connection relation, particularly adopts the process of coating the carbon rod and the metal parts by carbon fiber prepreg or further adopts the combination of gluing and the carbon fiber prepreg coating mode for use, so that a sandwich structure is formed between the metal parts and carbon fiber materials to increase the combination interface between the spoke body and the tooth caps and the cap heads of the metal parts at two ends, the binding force between the spoke body and the metal parts at two ends is greatly improved, and simultaneously, the spoke inner core and the metal parts are combined by an inverted cone structure, thereby ensuring that the spoke body and the metal parts cannot slip off, improving the structural strength of the product, and.

The above description is only an embodiment utilizing the technical content of the present disclosure, and any modification and variation made by those skilled in the art can be covered by the claims of the present disclosure, and not limited to the embodiments disclosed.

Claims

1. The utility model provides an inner core butt joint integrated into one piece spoke which characterized in that: including first carbon-point inner core, second carbon-point inner core and carbon fiber prepreg layer, first carbon-point inner core butt joint second carbon-point inner core, the outer end of first carbon-point inner core and second carbon-point inner core is the great end of diameter and overlaps respectively and establishes cap head and dental cap, first carbon-point inner core, second carbon-point inner core and dental cap, the cap head is equipped with carbon fiber prepreg layer outward, wherein the cap head is equipped with the head that the flower-drum is connected in the cooperation, the dental cap is equipped with the screw tooth portion that the rim is connected in the cooperation, the head of cap head and the screw tooth portion of dental cap are located the outside of carbon fiber prepreg layer.

2. The internal core butt joint integrally-formed spoke according to claim 1, wherein: the carbon fiber prepreg layer is formed by winding carbon fiber prepreg on a first carbon rod inner core, a second carbon rod inner core, a dental cap and a cap head and heating in a die; the outer ends of the first carbon rod inner core and the second carbon rod inner core are of inverted cone structures, the diameter D of the maximum end of the two carbon rod inner cores is larger than the diameter D of the minimum end of the two carbon rod inner cores, and D/D is larger than or equal to 1.3 and is larger than or equal to 2.

3. An inner core butt joint integrally formed spoke according to claim 1 or 2, wherein: the center of the cap head is provided with a mounting hole, the mounting hole comprises a conical hole section and a straight hole section, and the maximum inner diameter of the conical hole section is smaller than the maximum outer diameter of the first carbon rod inner core inverted cone structure;

4. The internal core butt joint integrally-formed spoke according to claim 1, wherein: the cap head and the dental cap are provided with conical extending parts for winding and connecting carbon fiber prepreg, and anti-falling bosses are arranged on the peripheries of the conical extending parts of the cap head and the dental cap so as to improve the binding force of the carbon fiber prepreg coating.

5. A preparation method of an inner core butt joint integrally-formed spoke is characterized by comprising the following steps:

s1, preparing a carbon rod inner core:

and S6, opening the mold after molding, taking out, and then processing screw teeth on the second metal piece to obtain the final usable product.

6. The method for preparing the inner core butting integrally formed spoke according to claim 5, wherein the method comprises the following steps: in step S1, the first carbon rod inner core and the second carbon rod inner core are carbon rod inner cores of the same specification, and a carbon fiber rod body is formed by die molding or pultrusion, and the diameter of the cylinder part of the carbon rod inner core is smaller than 1.8 mm.

7. The method for preparing the inner core butting integrally formed spoke according to claim 5, wherein the method comprises the following steps: in step S2, the peripheries of the opposite ends of the first metal piece and the second metal piece are both tapered, and the through hole in the middle of the two metal pieces includes a tapered section to match with the enlarged portion of the corresponding carbon rod inner core;

in the step S2, the peripheral sides of the first metal piece and the second metal piece are both processed into a concave-convex design so as to improve the bonding force of the carbon fiber prepreg coated metal piece; the second metal piece is provided with a linear clamping groove on the outer side of the concave-convex design.

8. The method for preparing the inner core butting integrally formed spoke according to claim 5, wherein the method comprises the following steps: before step S3, two metal pieces and the corresponding carbon rod inner core need to be coarsened, and the surface of the head of the carbon rod inner core is coated with high-strength high-temperature-resistant bonding glue and is connected and bonded with the corresponding metal pieces;

9. The method for preparing the inner core butting integrally formed spoke according to claim 5, wherein the method comprises the following steps: in step S5, the temperature is controlled at 180 ℃ for 50-70 minutes during heating and molding;

in step S5, the spoke shape is a cross-sectional shape such as a circle, a flat shape, an oval shape, or a substantially diamond shape.

10. A method for preparing an inner core butt joint integrally formed spoke according to any one of claims 5 to 9, which is characterized in that: in step S6, the screw thread end of the second metal piece on the spoke is matched with and assembled with a screw cap, and the first metal piece of the spoke has a cap head structure.